From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Dave Chinner <david@fromorbit.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 14/21] xfs: cross-reference with the bnobt
Date: Mon, 8 Jan 2018 16:34:41 -0800 [thread overview]
Message-ID: <20180109003441.GB5602@magnolia> (raw)
In-Reply-To: <20180108235125.GG16421@dastard>
On Tue, Jan 09, 2018 at 10:51:25AM +1100, Dave Chinner wrote:
> On Fri, Dec 22, 2017 at 04:44:18PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> >
> > When we're scrubbing various btrees, cross-reference the records with
> > the bnobt to ensure that we don't also think the space is free.
> >
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > ---
> > fs/xfs/scrub/agheader.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++
> > fs/xfs/scrub/alloc.c | 19 +++++++++++
> > fs/xfs/scrub/bmap.c | 21 +++++++++++-
> > fs/xfs/scrub/btree.c | 12 +++++++
> > fs/xfs/scrub/ialloc.c | 1 +
> > fs/xfs/scrub/inode.c | 15 ++++++++
> > fs/xfs/scrub/refcount.c | 1 +
> > fs/xfs/scrub/rmap.c | 4 ++
> > fs/xfs/scrub/scrub.h | 5 +++
> > 9 files changed, 161 insertions(+), 1 deletion(-)
> >
> >
> > diff --git a/fs/xfs/scrub/agheader.c b/fs/xfs/scrub/agheader.c
> > index 5be9059..3bb0f96 100644
> > --- a/fs/xfs/scrub/agheader.c
> > +++ b/fs/xfs/scrub/agheader.c
> > @@ -107,6 +107,20 @@ xfs_scrub_superblock_xref(
> > struct xfs_scrub_context *sc,
> > struct xfs_buf *bp)
> > {
> > + struct xfs_mount *mp = sc->mp;
> > + xfs_agnumber_t agno = sc->sm->sm_agno;
> > + xfs_agblock_t bno;
> > + int error;
> > +
> > + bno = XFS_SB_BLOCK(mp);
>
> agbno
Fixed (and all the others).
> > +
> > + error = xfs_scrub_ag_init(sc, agno, &sc->sa);
> > + if (!xfs_scrub_xref_process_error(sc, agno, bno, &error))
> > + return;
> > +
> > + xfs_scrub_xref_not_free(sc, &sc->sa.bno_cur, bno, 1);
>
> "xref_not_free". That doesn't tell me what it's actually checking
> is not free, or what it's checking against. Seeing as we're checking
> these all against the bnobt, wouldn't something like this be more
> obvious:
>
> xfs_scrub_is_used_space(sc, agbno, 1);
I've been trying to keep "xref" in the name of the functions that help
us do cross-referencing, but you're right that the **pcur parameter can
drop out. I'll ... do that. :)
> > + /* scrub teardown will take care of sc->sa for us */
> > }
> >
> > /*
> > @@ -407,11 +421,51 @@ xfs_scrub_superblock(
> >
> > /* AGF */
> >
> > +/* Tally freespace record lengths. */
> > +STATIC int
> > +xfs_scrub_agf_record_bno_lengths(
> > + struct xfs_btree_cur *cur,
> > + struct xfs_alloc_rec_incore *rec,
> > + void *priv)
> > +{
> > + xfs_extlen_t *blocks = priv;
> > +
> > + (*blocks) += rec->ar_blockcount;
> > + return 0;
> > +}
> > +
> > /* Cross-reference with the other btrees. */
> > STATIC void
> > xfs_scrub_agf_xref(
> > struct xfs_scrub_context *sc)
> > {
> > + struct xfs_mount *mp = sc->mp;
> > + struct xfs_agf *agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
> > + struct xfs_btree_cur **pcur;
> > + xfs_agblock_t bno;
> > + xfs_extlen_t blocks;
> > + int error;
> > +
> > + bno = XFS_AGF_BLOCK(mp);
>
> agbno. (and for all the others)
>
> > +
> > + error = xfs_scrub_ag_btcur_init(sc, &sc->sa);
> > + if (error)
> > + return;
> > +
> > + xfs_scrub_xref_not_free(sc, &sc->sa.bno_cur, bno, 1);
> > +
> > + /* Check agf_freeblks */
> > + pcur = &sc->sa.bno_cur;
> > + if (*pcur) {
> > + blocks = 0;
> > + error = xfs_alloc_query_all(*pcur,
> > + xfs_scrub_agf_record_bno_lengths, &blocks);
> > + if (xfs_scrub_should_xref(sc, &error, pcur) &&
> > + blocks != be32_to_cpu(agf->agf_freeblks))
> > + xfs_scrub_block_xref_set_corrupt(sc, sc->sa.agf_bp);
> > + }
>
> I have no idea what xfs_scrub_should_xref() means in this context.
> We're doing a xref scrub, so why are we asking if we should be
> running a xref?
Given that we tried to retrieve some data from some other data
structure, the function xfs_scrub_should_xref decides if we should
actually bother with the comparison checks? In other words, if the
xfs_alloc_query_all returned an error code then we need to delete *pcur
and we can skip the "blocks != be32..." check since it makes no sense.
How about xfs_scrub_should_check_xref?
>
>
> > diff --git a/fs/xfs/scrub/alloc.c b/fs/xfs/scrub/alloc.c
> > index 0d95b84..3d6f8cc 100644
> > --- a/fs/xfs/scrub/alloc.c
> > +++ b/fs/xfs/scrub/alloc.c
> > @@ -114,3 +114,22 @@ xfs_scrub_cntbt(
> > {
> > return xfs_scrub_allocbt(sc, XFS_BTNUM_CNT);
> > }
> > +
> > +/* xref check that the extent is not free */
> > +void
> > +xfs_scrub_xref_not_free(
> > + struct xfs_scrub_context *sc,
> > + struct xfs_btree_cur **pcur,
> > + xfs_agblock_t bno,
> > + xfs_extlen_t len)
> > +{
> > + bool is_freesp;
> > + int error;
> > +
> > + if (!(*pcur))
> > + return;
> > +
> > + error = xfs_alloc_has_record(*pcur, bno, len, &is_freesp);
> > + if (xfs_scrub_should_xref(sc, &error, pcur) && is_freesp)
> > + xfs_scrub_btree_xref_set_corrupt(sc, *pcur, 0);
> > +}
>
> Again, "should_xref" doesn't actually tell me anything about what
> this function is doing...
>
> > @@ -117,6 +117,25 @@ xfs_scrub_bmap_extent_xref(
> > struct xfs_btree_cur *cur,
> > struct xfs_bmbt_irec *irec)
> > {
> > + struct xfs_scrub_ag sa = { 0 };
> > + struct xfs_mount *mp = info->sc->mp;
> > + xfs_agnumber_t agno;
> > + xfs_agblock_t agbno;
> > + xfs_extlen_t len;
> > + int error;
> > +
> > + agno = XFS_FSB_TO_AGNO(mp, irec->br_startblock);
> > + agbno = XFS_FSB_TO_AGBNO(mp, irec->br_startblock);
> > + len = irec->br_blockcount;
> > +
> > + error = xfs_scrub_ag_init(info->sc, agno, &sa);
> > + if (!xfs_scrub_fblock_process_error(info->sc, info->whichfork,
> > + irec->br_startoff, &error))
> > + return;
> > +
> > + xfs_scrub_xref_not_free(info->sc, &sa.bno_cur, agbno, len);
> > +
> > + xfs_scrub_ag_free(info->sc, &sa);
>
> Why do we use an on-stack struct xfs_scrub_ag here, and not the one
> embedded into the scrub context like all the other functions in this
> patch?
I think this is an archaic side effect of a previous version of scrub
when the xfs_scrub_ag wasn't embedded in the scrub context. :/
IOWs, there's no reason, I'll go fix it (and the others).
--D
> > }
> >
> > /* Scrub a single extent record. */
> > diff --git a/fs/xfs/scrub/btree.c b/fs/xfs/scrub/btree.c
> > index 9151499..ae58fcc 100644
> > --- a/fs/xfs/scrub/btree.c
> > +++ b/fs/xfs/scrub/btree.c
> > @@ -381,9 +381,12 @@ xfs_scrub_btree_check_block_owner(
> > struct xfs_scrub_ag sa = { 0 };
> > struct xfs_scrub_ag *psa;
> > xfs_agnumber_t agno;
> > + xfs_agblock_t bno;
> > + bool is_freesp;
> > int error = 0;
> >
> > agno = xfs_daddr_to_agno(bs->cur->bc_mp, daddr);
> > + bno = xfs_daddr_to_agbno(bs->cur->bc_mp, daddr);
>
> agbno.
>
> > @@ -584,6 +584,21 @@ xfs_scrub_inode_xref(
> > xfs_ino_t ino,
> > struct xfs_dinode *dip)
> > {
> > + struct xfs_scrub_ag sa = { 0 };
> > + xfs_agnumber_t agno;
> > + xfs_agblock_t agbno;
> > + int error;
> > +
> > + agno = XFS_INO_TO_AGNO(sc->mp, ino);
> > + agbno = XFS_INO_TO_AGBNO(sc->mp, ino);
> > +
> > + error = xfs_scrub_ag_init(sc, agno, &sa);
> > + if (!xfs_scrub_xref_process_error(sc, agno, agbno, &error))
> > + return;
> > +
> > + xfs_scrub_xref_not_free(sc, &sa.bno_cur, agbno, 1);
> > +
> > + xfs_scrub_ag_free(sc, &sa);
>
> Same question here - on-stack vs embedded....
>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@fromorbit.com
> --
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next prev parent reply other threads:[~2018-01-09 0:34 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-23 0:42 [PATCH v11 00/21] xfs: online scrub xref support Darrick J. Wong
2017-12-23 0:42 ` [PATCH 01/21] xfs: ignore agfl read errors when not scrubbing agfl Darrick J. Wong
2018-01-05 1:12 ` Dave Chinner
2017-12-23 0:43 ` [PATCH 02/21] xfs: catch a few more error codes when scrubbing secondary sb Darrick J. Wong
2018-01-05 1:17 ` Dave Chinner
2018-01-05 1:24 ` Darrick J. Wong
2018-01-05 2:10 ` Dave Chinner
2017-12-23 0:43 ` [PATCH 03/21] xfs: xfs_scrub_bmap should use for_each_xfs_iext Darrick J. Wong
2018-01-05 1:17 ` Dave Chinner
2017-12-23 0:43 ` [PATCH 04/21] xfs: always grab transaction when scrubbing inode Darrick J. Wong
2018-01-05 1:18 ` Dave Chinner
2017-12-23 0:43 ` [PATCH 05/21] xfs: distinguish between corrupt inode and invalid inum in xfs_scrub_get_inode Darrick J. Wong
2018-01-05 1:23 ` Dave Chinner
2017-12-23 0:43 ` [PATCH 06/21] xfs: add scrub cross-referencing helpers for the free space btrees Darrick J. Wong
2018-01-05 1:29 ` Dave Chinner
2017-12-23 0:43 ` [PATCH 07/21] xfs: add scrub cross-referencing helpers for the inode btrees Darrick J. Wong
2018-01-05 1:36 ` Dave Chinner
2018-01-05 2:19 ` Darrick J. Wong
2018-01-05 21:51 ` [PATCH v2 " Darrick J. Wong
2018-01-16 23:05 ` Darrick J. Wong
2018-01-17 0:36 ` Dave Chinner
2017-12-23 0:43 ` [PATCH 08/21] xfs: add scrub cross-referencing helpers for the rmap btrees Darrick J. Wong
2018-01-05 1:40 ` Dave Chinner
2018-01-05 2:49 ` Darrick J. Wong
2018-01-05 3:38 ` Dave Chinner
2018-01-05 21:53 ` [PATCH v2 " Darrick J. Wong
2018-01-06 20:46 ` Dave Chinner
2017-12-23 0:43 ` [PATCH 09/21] xfs: add scrub cross-referencing helpers for the refcount btrees Darrick J. Wong
2018-01-05 1:41 ` Dave Chinner
2017-12-23 0:43 ` [PATCH 10/21] xfs: set up scrub cross-referencing helpers Darrick J. Wong
2018-01-05 2:08 ` Dave Chinner
2018-01-05 3:05 ` Darrick J. Wong
2018-01-05 21:54 ` [PATCH v2 " Darrick J. Wong
2018-01-16 23:06 ` Darrick J. Wong
2018-01-17 0:41 ` Dave Chinner
2017-12-23 0:44 ` [PATCH 11/21] xfs: fix a few erroneous process_error calls in the scrubbers Darrick J. Wong
2018-01-05 2:11 ` Dave Chinner
2017-12-23 0:44 ` [PATCH 12/21] xfs: check btree block ownership with bnobt/rmapbt when scrubbing btree Darrick J. Wong
2018-01-05 2:24 ` Dave Chinner
2018-01-05 2:53 ` Darrick J. Wong
2018-01-05 3:39 ` Dave Chinner
2017-12-23 0:44 ` [PATCH 13/21] xfs: introduce scrubber cross-referencing stubs Darrick J. Wong
2018-01-08 23:36 ` Dave Chinner
2018-01-08 23:59 ` Darrick J. Wong
2018-01-09 21:00 ` [PATCH v2 " Darrick J. Wong
2018-01-10 0:12 ` Dave Chinner
2017-12-23 0:44 ` [PATCH 14/21] xfs: cross-reference with the bnobt Darrick J. Wong
2018-01-08 23:51 ` Dave Chinner
2018-01-09 0:34 ` Darrick J. Wong [this message]
2018-01-09 0:57 ` Dave Chinner
2018-01-09 21:15 ` [PATCH v2 " Darrick J. Wong
2018-01-10 0:15 ` Dave Chinner
2017-12-23 0:44 ` [PATCH 15/21] xfs: cross-reference bnobt records with cntbt Darrick J. Wong
2018-01-08 23:55 ` Dave Chinner
2018-01-09 0:37 ` Darrick J. Wong
2018-01-09 21:20 ` [PATCH v2 " Darrick J. Wong
2018-01-10 0:19 ` Dave Chinner
2017-12-23 0:44 ` [PATCH 16/21] xfs: cross-reference inode btrees during scrub Darrick J. Wong
2018-01-09 21:22 ` [PATCH v2 " Darrick J. Wong
2018-01-15 22:17 ` Dave Chinner
2018-01-16 6:30 ` Darrick J. Wong
2018-01-16 23:23 ` [PATCH v3 " Darrick J. Wong
2018-01-17 0:44 ` Dave Chinner
2017-12-23 0:44 ` [PATCH 17/21] xfs: cross-reference reverse-mapping btree Darrick J. Wong
2018-01-09 21:24 ` [PATCH v2 " Darrick J. Wong
2018-01-15 23:04 ` Dave Chinner
2018-01-16 6:38 ` Darrick J. Wong
2018-01-16 23:25 ` [PATCH v3 " Darrick J. Wong
2018-01-17 0:52 ` Dave Chinner
2017-12-23 0:44 ` [PATCH 18/21] xfs: cross-reference the rmapbt data with the refcountbt Darrick J. Wong
2018-01-09 21:25 ` [PATCH v2 " Darrick J. Wong
2018-01-15 23:49 ` Dave Chinner
2018-01-16 6:49 ` Darrick J. Wong
2018-01-16 19:47 ` Darrick J. Wong
2018-01-16 23:26 ` [PATCH v3 " Darrick J. Wong
2018-01-17 1:00 ` Dave Chinner
2018-01-17 1:11 ` Darrick J. Wong
2017-12-23 0:44 ` [PATCH 19/21] xfs: cross-reference refcount btree during scrub Darrick J. Wong
2018-01-09 21:25 ` [PATCH v2 " Darrick J. Wong
2018-01-16 2:44 ` Dave Chinner
2018-01-16 6:52 ` Darrick J. Wong
2018-01-16 20:26 ` Darrick J. Wong
2018-01-16 23:27 ` [PATCH v3 " Darrick J. Wong
2018-01-17 1:02 ` Dave Chinner
2017-12-23 0:44 ` [PATCH 20/21] xfs: cross-reference the realtime bitmap Darrick J. Wong
2018-01-09 21:26 ` [PATCH v2 " Darrick J. Wong
2018-01-16 2:57 ` Dave Chinner
2018-01-16 6:55 ` Darrick J. Wong
2018-01-16 23:27 ` [PATCH v3 " Darrick J. Wong
2018-01-17 1:03 ` Dave Chinner
2017-12-23 0:45 ` [PATCH 21/21] xfs: cross-reference the block mappings when possible Darrick J. Wong
2018-01-09 21:26 ` [PATCH v2 " Darrick J. Wong
2018-01-16 2:58 ` Dave Chinner
2018-01-16 6:55 ` Darrick J. Wong
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